Use of an expert system to perform trip reliability quantification calculations

ICI applies a rigorous, six stage hazard study process during project execution to identify and eliminate potential hazards. If the risk cannot be eliminated, it must be evaluated, so that the worst credible event is fully understood, and suitable risk reduction measures taken. One commonly used method of reducing the risk is to install trip and alarm systems to detect abnormal operation and allow safe shutdown of the plant. An initial package has been developed to execute the required calculations. The package is able to handle a number of trip system configurations, up to 3 input and 3 outputs. The user is led interactively through the calculation by either selecting from the displayed options or by answering simple questions. The programme draws data from flexible databases containing general equipment reliability data. The data tables can be readily enhanced to include local operating experience/data available from the user. The system provides details of the calculations in standard format. This output can be tailored to meet the users needs